IfcRevolvedAreaSolidTapered

实体定义

如果将截面沿圆弧旋转，则定义为实心锥形。横截面可沿旋转扫描从起始横截面形状变为末端横截面形状。然后连接起始和结束横截面的相应顶点。有界曲面可能有孔，这些孔将扫入实体中的孔中。

旋转轴定义为：

起点：自我IfcSweptAreaSolid.Position.位置

方向：自我IfcrVolvedAreaSolid.轴

旋转轴：自身ifcRevedAreaSolid.AxisLine，通过应用1个单位的幅值从起点和方向创建。

方向：当观察旋转轴的正方向时，正角度按顺时针方向应用。

起始横截面由SELF定义IfcSweptAreaSolid.SweptArea:

位于由SELF定义的位置坐标系的XY平面上的有界平面IfcSweptAreaSolid.位置.P[1]和SELFIfcSweptAreaSolid.位置.P[2]

旋转轴位于起始横截面的平面内，但不得与起始横截面的内部相交。

端部横截面由端部截面积定义：

位于位置坐标系XY平面上的有界平面，通过旋转SELF提供的起始位置坐标来定义IfcSweptAreaSolid.位置以自定角度绕旋转轴旋转Ifcredovedareasolid.角度.

结束横截面在拓扑上类似于起始横截面（具有相同数量的顶点和边）。

端部横截面既可以由使用不同参数值的同一参数轮廓定义，也可以通过端部横截面平面内起始轮廓的二维笛卡尔变换来定义。

实体是通过将起始横截面转换为终点横截面而生成的。一个起始面、一个端面（每个由起始和结束横截面定义）和一个或多个侧面。每个侧面是一个直纹面，由起始和结束截面的一对对应边定义。直纹曲面是在超类型IfcRevolvedAreaSolid定义的柱坐标空间中构造的。

IFC4中增加的新实体。

非正式提议：

内部镜像IfcDerivedProfileDef.运算符不得使用

Formal Propositions

Rule	Description
CorrectProfileAssignment	The SweptArea as start profile and the EndSweptArea as end profile shall be compatible.

 

#	Attribute	Type	Cardinality	Description	C
IfcRepresentationItem
	LayerAssignment	IfcPresentationLayerAssignment @AssignedItems	S[0:1]	Assignment of the representation item to a single or multiple layer(s). The LayerAssignmentscan override a LayerAssignments of the IfcRepresentation it is used within the list of Items.	X
	StyledByItem	IfcStyledItem @Item	S[0:1]	Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.	X
IfcGeometricRepresentationItem
IfcSolidModel
	Dim :=3	IfcDimensionCount	[1:1]	The space dimensionality of this class, it is always 3.	X
IfcSweptAreaSolid
1	SweptArea	IfcProfileDef	[1:1]	The surface defining the area to be swept. It is given as a profile definition within the xy plane of the position coordinate system.	X
2	Position	IfcAxis2Placement3D	[0:1]	Position coordinate system for the resulting swept solid of the sweeping operation. The position coordinate system allows for re-positioning of the swept solid. If not provided, the swept solid remains within the position as determined by the cross section or by the directrix used for the sweeping operation.	X
IfcRevolvedAreaSolid
3	Axis	IfcAxis1Placement	[1:1]	Axis about which revolution will take place.	X
4	Angle	IfcPlaneAngleMeasure	[1:1]	The angle through which the sweep will be made. This angle is measured from the plane of the swept area provided by the XY plane of the position coordinate system.	X
	AxisLine :=IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcCurve() || IfcLine(Axis.Location, IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcVector(Axis.Z,1.0))	IfcLine	[1:1]	The line of the axis of revolution.	X
IfcRevolvedAreaSolidTapered
5	EndSweptArea	IfcProfileDef	[1:1]		X

EXPRESS Specification

ENTITY IfcRevolvedAreaSolidTapered
 SUBTYPE OF (IfcRevolvedAreaSolid);
  EndSweptArea : IfcProfileDef;
 WHERE
  CorrectProfileAssignment : IfcTaperedSweptAreaProfiles(SELFIfcSweptAreaSolid.SweptArea, SELF.EndSweptArea);
END_ENTITY;